Having listened and played around with it for 3 days, this is, with no reservation, the best DAP I've ever had; it's so much better than the Sony A it's not funny.

Holding it in my left hand, just using my thumb and 3 fingers, all the important button functions are available to me: volume, next/previous track, pause, screen on/off and sleep. A quick press of a button, the screen lights up and every other function is availlable to me - just using my thumb.

Cowon's sound enhancements are excellent; the UI is smooth, fluid and user-friendly; video is handled well, battery life is superb.

I haven't bothered with themes, or even updated the firmware, the player's core function of playing audio and video - and doing it brilliantly - is stellar..and it doesn't get any better than that for me.

Aero Music (music UCI):
- Multiple on-the-fly playlists
- EQ Editor with preset names
- Mini queue (select the next track to be played)
- LRC and TXT lyrics support (yeah, I know, the J3 has native LRC support for some weeks, but I heard it sucks)
- Horizontal music UI (replaces Cowon's crappy coverflow; el maco's flow browser is supported, so you get a better coverflow implementation)
- Access to all music-related options
- Maybe other stuff I forgot to mention

how do you get the horizontal music screen to come up like in the previous picture?

I'm guessing you really have two questions here: (1) how do you get into landscape mode, and (2) how to do you get the background wallpaper image to appear on the entire landscape desktop?

I just installed Aero today, so I've been experimenting a bit myself, trying to figure out how things work. There's no actual documentation that I can find, so it's a matter of how intuitive is the interface which determines whether the novice user can make a good guess as to what's where.

Anyway, I can certainly answer both questions above, based on the results of my first-day trial and error.

(1) The default setting as delivered is "portrait mode locked". So although you want to enter landscape mode as you did with the Cowon UI, simply by twisting the player 90 degrees, nothing happens with Aero when you do that... with the default installed setttings.

You have to UNLOCK "portrait mode", to enable "swing mode" which presents either landscape or portrait mode depending on the J3's orientation.

To UNLOCK "portrait mode" you have to get into Aero's settings to customize this function. Since you're currently locked in "portrait mode", first you need to make the menu appear by tapping on the down-arrow in the center of the control bar just over the album art. This causes a dropdown second row of controls, which is actually the 3-page menu bar.

By default, that second row appears with you looking at page 1 of the menu, which contains four buttons: (1) Jet Audio BBE, (2) haven't figured out yet, (3) volume, and (4) track list preview.

Now finger-gesture slide that second row "menu" bar to the left one page, so that you're now looking at a second set of four buttons: (1) Aero settings, (2) portrait/landscape lock mode, (3) don't know because it's grayed out, and (4) multi-purpose shuffle/repeat/folder play mode control.

If you tap the second button on page 2, ie. "portrait/landscape lock mode", repeatedly until you see an icon which is extremely tiny vertical white rectangle with an almost invisible gray horizontal rectangle slightly superimposed and over to the right, that's the icon for "swing mode enabled". You're now enabled for landscape or portrait mode.

Now tap the "up arrow" button on the first control row, and the second row will vanish.

NOTE: Aero settings (which you get into by tapping the first button on page 2 of the menu, obtained by the preliminary steps above) has unique settings for "landscape mode config" and "portrait mode config". They're not identical, but they are unique for each mode. General settings which apply to both presentation modes are grouped under "general config".

(2) Now once you're in landscape mode, there are three separate presentations you can select: the mode in the screenshot above is what I'm guessing is "album art wallpaper". I believe the background shown in that screenshot is your album art from whatever track you're playing, but stretched to fill the entire desktop space. It's also made mostly transparent so that the track information superimposed over it can be read clearly.

It's also scrolled vertically ever so slowly first down and then up.

Now landscape mode's three different presentations are navigated through by finger-swiping horizontally, again as if there were "three pages" of presentation views. Doesn't really matter where you touch your finger to the screen, just touch it somewhere and swipe left or right.

This horizontal swipe left or right action will navigate landscape mode to either (1) standard landscape view, with the album art at the left and slightly reduced in size, or (2) showcase view, with the album art in the center of the screen and slightly increased in size.

In both of these two landscape mode views where album art is displayed, I don't believe either album art is in full-size (as it is in portrait mode when you have "seekbar style" set to "even simpler"). This is slightly disappointing, but that's the way it works right now. Personally, I wish album art could somehow be configured as full-size in landscape mode, but it's not.

NOTE: in landscape mode the control bar at the bottom of the screen doubles as the menu bar. So if you swipe it to the left or right, you will see the menu control buttons (as you do in portrait mode when you tap the down-arrow on the upper control bar). When you're done doing whatever you want in the menu area, swipe again until you get back to the three player control buttons.

I have found - to my chagrin - that battery life on the J3 isn't as good as my Sony... I think there's something I'm not quite doing right, like not coming out of the Music menu before putting it to sleep... but it seems to just be around 30 hours with minimal screen use or button pressing.

^ hmmm, J3 is supposed to do manufacturer battery life something like 50hours right? 30 hours, even accounting for real world usage does seem a bit too low to me. Just read a couple threads just now on iAudiophile. Ya got a card in that thing? A 32GB? Seems perhaps some suspicion about 32GB cards and possibly impacted battery life...

Nah, just an 16Gb.. I've perused various threads and not come to any definitive answer.

I either have it on BBE Viva2 or my own, fairly moderate, custom EQ, playing lossy mp3s @ around 200kbps.

I come out of any menus before putting it in sleep, and I've tried just powering down completely. I just don't know, but the S754 definitely outlasts it playing the same files.

This is the only (slight, I say slight, because it's still 30 hours+) disappointment with the J3. I'm going to try completely draining it next, then try USB charging instead of my laptop. It's still just about the best player I've ever tried (ergonomics - I can do everything with my left hand).

I had enough problems with "sleep" mode killing my battery overnight that I've given up on it entirely. Battery time turning the machine on/off is much better. I just keep my card out unless I'm planning on watching a film.

Never had many (and many different brands; and expensive ones) mp3/media players.
Always had some decent Sony tiny mp3s & the good-old Creative ZEN...
All I had were like... Crystal Palace, comparing with... LIVERPOOL (okay, you got me, I'm "Red"!).
I mean... the J3 seems to me like a bloody... FERRARI, when my good-old mp3/media players were... Audi Corsa!